ByJohn Worrall, Special to The Christian Science MonitorFebruary 1, 1982

Nairobi, Kenya
— The world's children are being asked to send trees to the third world.

''For every child a tree'' is the name of the drive by the UN Environment Program.

Deforestation has worsened over the past decade. A third of the world depends on firewood for cooking, boiling water, and heating homes. But in many regions wood gatherers - and they are often children - have to walk farther and farther to gather their bundles.

The daunting challenge is to replace billions of trees in Africa, Asia, and Latin America, where wide swaths of land are rapidly becoming treeless deserts. If each child in the developed world sent enough money to plant one tree in these areas, it would make a big difference, UNEP environmentalists say.

Some 5,000 children's libraries throughout the world are being asked to hold workshops for children on the need for trees and to explain soil erosion, desertification, and energy.